In general, an air conditioner is a device which maintains indoor air using a refrigeration cycle so as to be suitable for human activities. A conventional air conditioner may cool or heat air near a heat exchanger according to a phase change of a refrigerant flowing in the heat exchanger, and discharge the cooled or heated air to an indoor area, and thus an indoor temperature may be suitably maintained.
Such an air conditioner includes a refrigeration cycle in which a refrigerant circulates among a compressor, a condenser, an expansion valve, and an evaporator in a forward or backward direction, and the compressor provides the refrigerant having a high temperature and high pressure gas state and the condenser provides the refrigerant having a room temperature and high pressure liquid state. The expansion valve depressurizes the refrigerant having a room temperature and high pressure liquid state, and the evaporator evaporates the depressurized refrigerant into a low temperature gas state.
The air conditioner may be classified into a separated air conditioner in which an outdoor unit and an indoor unit are separately installed from each other, and an integrated air conditioner in which an outdoor unit and an indoor unit are integrally installed with each other.